The overall goal of this project is to develop and commercialize a new sensor system for patient monitoring that will measure both oxygen and carbon dioxide in the muscle. These measurements can be used to predict the early onset of hemorrhagic shock, quantify the efficacy of cardiac resuscitation, and improve the standard of care for critically ill patients. To accomplish this goal, novel technology will be utilized to make very small and highly accurate sensors for measuring oxygen or carbon dioxide in tissue. These sensors will not require on site calibration and can be easily and quickly implanted in tissue. The sensor systems will be small and robust, weighing only a few ounces and they will be battery operated. The sensor system is intended to perform reliably in the field under difficult conditions as well as in fully equipped medical facilities. Care will be taken at every level to assure optimal performance, ease of use, and tight integration into the applicable clinical environment. This sensor system will substantially improve the care of critically ill patients, particularly those suffering from acute trauma. PUBLIC HEALTH RELEVANCE: This proposal will result in a medical device that will improve the monitoring capabilities for critical care patients and for patients undergoing CPR. The device will accurately monitor oxygen levels in muscle to give an accurate measure of how the circulation is functioning. The product is designed to be used by first responders in field situations, and in the ICU.